The Question:

I have had a unsuccessful search for the origin of the
abbreviation "lbs." which is used for pounds. What does it stand for,
and where did it come from?

The Answer:

The abbreviation .lbs is based on the word "libra." A libra was
the basic unit of weight used by Ancient Romans. It was almost
equivalent to today's English pound. The word is Latin and it means
"balance," or "the scales."

The libra is still a basic unit of weight in Italy, Spain,
Portugal, and other Spanish-speaking countries in the Americas.